Key words

Foreign objects, Apexification, MTA, periradicular surgery

Introduction

Pulp necrosis of an immature permanent tooth, from the trauma or caries arrests further tooth development. As the root development takes long time, an incompletely formed apex is one of the most common features seen in traumatized teeth. The treatment of such teeth can be complicated with the presence of foreign objects in the canal or in the periapical region. Foreign objects may become a potent source of pain and infection. In such cases, the presence of foreign body is detected on routine radiographs. The following report describes a case of nonvital immature permanent tooth with foreign object impacted in the periapical region. The treatment included retrieval of foreign object through periapical surgery followed by retrograde sealing with MTA.

A major problem associated with the endodontic treatment of teeth that contain pulpal necrosis with open apices is achieving an acceptable seal in the apical area. In the past, the main goal was creating a barrier with hard tissue at the end of the root, a procedure known as apexification, in order to limit bacterial infection and establish a suitable environment for the induction of calcified tissue in the apical area.(1,2) Materials previously considered for apical barriers include dentin chips, freeze dried cirtical bone/ dentin, calcium phosphate and calcium hydroxide which are efficient in creating a barrier for obturation in one appointment but do not provide a well sealed environment. Thus MTA has been advocated for use as an apical barrier because of its sealing capabilities, ability to set in the presence of moisture, its biocompatibility and ability to induce hard tissue formation. (3,4)

Case Report

10 year old male patient reported to our department with a chief complain of pus discharge from maxillary anterior region. Clinical examination revealed fractured 11, 21, with slight swelling in relation to 11 and pus discharge from the vestibule.(Fig 1) Patient gave history of trauma to the concerned teeth 2 years back, for which he had consulted a local dentist. Radiographic examination revealed large periapical lesion surrounding the roots of 11 and wide open apices.(Fig 2) In the periradicular area some radiopaque shadows were present. The canal of 21 was also wide but the apex was closed with elongation of root in apical third and some radiopaque material was present in the canal. Medical history of the patient was in significant.

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Root canal therapy followed by apexification was planned in 11 and 21. Cleaning of the root canal system began with removal of the radiooapue material from 21 (which was found to be metapex) and necrotic tissue from11.(Fig 3) Debridement was

performed with Flexofile files and 2.5% sodium chlorite was used as irrigant solution. The use of files was done to a limited extent because it might further weaken the thin dentinal walls. Completed removal of metapex was done from 21. There was no need apexification in 21, because it showed presence of apical stop both clinically and radiographically.

Copious irrigation was performed in 11, the canal was cleaned and dried. On the next visit calcium hydroxide was placed in the canals, the access cavity was sealed with cavit and the patient was recalled after 3 weeks, but the patient returned after 2 days with pain and pus discharge in relation to 11. The temporary restoration was removed and the canal was irrigated with sodium hydroxide. Several failed attempts in providing a coronal seal and recurrence of pus discharge lead to the decision of periapical surgery followed by retrograde apexification with MTA.

The surgical area was disinfected with iodine solution and 0.12% chlorhexidine gluconate. Flap design consisted of 2 releasing incisions connected by a sulcular incision. A full-thickness mucoperiosteal flap was reflected and bony defect was checked with a probe. After removal of granulomatous tissue from the osseos cavity, the cavity was enlarged with a surgical bur. Saline solution was used for irrigation during the entire procedure. In the periradicular area the granulomatous tissue was carefully curetted with surgical curette. Several foreign object were found during the removal of the granulation tissue from the osseos cavity.(Fig 4a) The presence of these might

have been the reason for failure of conventional endodontic treatment and the presence of radioopacities in the periradicular region on the radiograph.

After complete removal of granulation tissue from the osseos cavity, the root of the tooth was examined. Careful examination and instrumentation showed a defect on the distolateral aspect of the root, which might have occurred because of mechanical instrumentation during previous dental treatment.(Fig 4b) As planned before, retrograde filling was done with MTA (MTA-Pro Root, Dentsply, Tulsa Dental

Company).(Fig 5) Wet cotton was packed in the canal from the access cavity to aid in condensation of MTA. After placement of wet cotton MTA was condensed from the root end till the level of the dentinal defect. The wet cotton was left in the canal. The osseous cavity was allowed to fill with blood and the flap was repositioned and sutured.(Fig 6) Postoperative medication included an antibiotic, a nonsteroidal anti-inflammatory drug, and a mouthrinse.

The canal was obturated with guuta- percha two days after the procedure.(Fig 7) The sutures were removed after 7 days. The esthetic buildup of the fractured teeth were done with composite resin (Esthet X HD, Dentsply).(Fig 8)

The patient returned for clinical and radiographic examinations 6 months and 12 months after the treatment. Follow-up showed progressive healing and clinically, there was no sinus track and no tenderness to palpation or percussion. Radiographic examination showed reduction in the size of the periapical lesion.(Fig 9)

Discussion

The discovery of foreign bodies in the teeth is a special situation, which is often diagnosed accidentally. It is more common to find this situation in children as it is a well-known fact that children often tend to have the habit of placing foreign objects in the mouth. Sometimes the foreign objects get stuck in the root canals of the teeth, which the children do not reveal to their parents due to fear. These foreign objects may act as a potential source of infection and may later lead to a painful condition. The objects can be pushed in the periapical region more easily in the teeth with wide open immature apex.(5) The presence of such objects can complicate the treatment of immature teeth which might then require a combination of periapical surgery followed by retrograde filling with MTA.

Periapical surgery with root- end resection is indicated in teeth with periapical pathosis where an orthograde revision is unlikely to resolve the periapical disease as in our case the presence of foreign objects in the periradicular area hampered the healing process. The surgical intervention also aims to remove the infected root-end and seal any remaining bacteria in the root canal system from the periradicular tissues.(6,7) The use of certain osteoinductive or osteoconductive materials such as human lypophilized bone in periradicular surgery has been indicated and might be very helpful in some situations for the success of the clinical case. The filling of the cavity with blood provided good results in our case which is also supported by Estrada PF who found that the use of membranes, bone graft, or their association did not influence the healing process.(8) The periapical surgery was followed by retrograde filling with MTA. Inserting MTA in the apical portion of the root after canal preparation favors the establishment of a healthy periodontal ligament as well as the new formation of bone and cementum. Due to its favorable histologic response, MTA has been considered a material that is effective as an apical barrier in cases of incomplete root formation. Its application results in predictable apical closing, reduced treatment time and a reduced number of radiographs taken.(9,10) Thus MTA was selected as material for apexification in our case.

A choice has to be made between orthograde or retrograde application of MTA. MTA was placed via retrograde technique in our case. Because orthograde delivery of MTA can be considered a more sensitive technique. Placement must be verified by radiography versus direct visualization from a retrograde direction, and condensation is limited due to minimal resistance of the open apex. In the present case the presence of lateral dentinal defect may have caused a problem in orthograde condensation of MTA. In addition to the difficulty in manipulating the material to the apex, the inherent irregularities and divergent nature of the tooth anatomy may affect its adaptation to the dentin walls, predisposing the material to marginal gaps at the dentin interface. (2)

Follow-up in our case showed progressive healing and clinically, there was no sinus track and no tenderness to palpation or percussion. Radiographic examination showed reduction in the size of the periapical lesion.

Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, location of the foreign body and the difficulty involved in its retrieval. Timely diagnosis and management of foreign object embedded in the tooth should be done to avoid further complication.